JPH02140927A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To remove contamination product and to remove a characteristic relating to quality of an insulating film itself for improving reliability by performing ozone treatment before forming an insulating film on a metal wiring. CONSTITUTION:After patterning a metal wiring 14 by dry etching, a resist 15 for masking is peeled off. Next, after performing heat treatment in an ozone containing atmosphere, an insulating film 17 is laminated by vapor growth or an application method. Accordingly, since a polymer 16 is completely removed by ozone treatment after etching of the metal wiring 14 and peeling-off of a resist 15, peeling-off of the interlayer insulating film 17 and a passivation film and a crack is excluded. Thereby, long term reliability also can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to a method for manufacturing a semiconductor device, and particularly to the growth of an insulating film on metal wiring formed by dry etching.

[Conventional technology]

Conventional method 1 For example, a method for manufacturing a semiconductor device having a multilayer wiring structure is as shown in FIG. After forming a contact hole through 22 and 23 to take out an electrode from the element, an AI2 alloy that will become the first metal wiring 24 is sputtered and patterned into a desired shape using a photoresist 25 (
In Fig. 2(a)), the metal wiring 24 is made of Ar1 or Al1 due to the electromigration characteristics changing due to miniaturization.
-3t is added with Cu. Next, photoresist 2
Using 5 as a mask, perform reactive ion etching (RI) using a halogen gas such as (1!, or BcI2a).
E) and electron cyclotron resonance etcher (ECR)
After dry etching and stripping the altered photoresist with 02 plasma, the photoresist residue and polymer remained, so it was treated with phenol-based stripper (12) and washed with water.

It is dry, but in order to further prevent Cu corrosion due to Clg, 0. Plasma stripping post-chamber, Freon gas such as CF, CHF, etc. is mixed into 02 in the same apparatus, and polymer 26 is intentionally deposited in the plasma, and then treated with a phenolic resist stripper. The interlayer insulating film 24 is then coated with SiH, 02 or N, at a low temperature of 450°C or less, to prevent corrosion from occurring in the air before being washed and dried (Fig. 2 (b)). A silicon oxide film is formed by a gas phase reaction of O gas under reduced pressure.First, a coated glass film 28 is applied to flatten the dead-edge portion of the first metal wiring 24, and after annealing, through holes are formed by photo-etching. A hole is opened and the second metal wiring 2
After AR gold alloy sputtering to give 9 (Fig. 2 (C)
)) The second metal wiring 29 is photo-etched using the same method as the first metal wiring 24, and then a passivation film is deposited by vapor phase growth, and a pad portion for taking out an external electrode is opened.

[Problem to be Solved by the Invention 1] However, with the prior art, it is difficult to completely remove the polymer 26 remaining after dry etching of the metal wiring 24°29 with a phenolic resist stripping solution, especially on the side surfaces of steps and grooves. leaves a lot of residue. The adhesion of interlayer films and passivation films formed on top of this, such as coating films, vapor-grown silicon oxide films, and silicon nitride films, was poor, and peeling and cracking occurred immediately after growth and due to stress during post-processing. . In addition, reliability was adversely affected due to contamination, and reproducibility was poor due to increased hole resistance.

However, the present invention solves this problem, and eliminates contamination in semiconductor devices, especially during wiring formation, and improves fine multi-functionality.
The purpose is to ensure a stable supply of semiconductor devices and to improve quality along with reliability.

[Means for Solving the Problems] The method for manufacturing a semiconductor device of the present invention includes a step of patterning metal wiring by dry etching, a step of peeling off a mask resist, and a step of heat treatment in an atmosphere containing ozone gas. , it is characterized by having a step of laminating an insulating film by electrophase growth or coating method.

[Embodiment 1] An embodiment of the present invention will be described below in detail based on FIG. 1.

When applied to a Si gate CMO3 semiconductor device with a submicron rule AI2 wiring two-layer structure, a semiconductor substrate on which semiconductor elements such as transistors and resistors are formed.
First and second field oxide films 12.13 are formed on the top by selective thermal oxidation or vapor phase growth, and a contact hole for taking out the electrode is formed. Sputtering AI2 alloy to a thickness of approximately 0.1 um.

Patterning the photoresist 15 (Fig. 1(a)
), then dry etching is performed using RIE containing CI2□ gas to form a first metal wiring 14 with a minimum dimension of 0.8 to 1.21 m and almost vertical side surfaces, and then continuously etched in the same chamber. Remove the resist using 02 plasma,
Subsequently, about 4% C/F3 was added to 02 to adhere polymer 16 in plasma (FIG. 1(b)), and then immersed in a phenolic resist stripping solution at about 90°C. Next, at about 380°C in a parallel plate plasma vapor phase growth apparatus,
About 5-6% ozone gas is mixed in 0□ and heated to 80 torr.
After completely removing the polymer 16 by processing for 60 seconds under the conditions of
It was grown to about 0.7 Lt m at orr. Next, for planarization, a coated glass film 18 is attached on top of this and annealed, and after opening a through hole, an AI2 layer containing Cu is applied. The alloy was sputtered to a thickness of about 1.0 μm, and photoetching and resist peeling were performed in the same process as the first metal wiring 14 to form the second metal wiring 19 (FIG. 1(d)).
After that, in a parallel plate plasma vapor phase epitaxy apparatus, after ozone treatment similar to the previous step, a silicon nitride film was grown by plasma to about 1.011 m at 1 torr using SiH4 and NHI as reaction gases to form a passivation film, and an external electrode was formed. A hole was made in the pad section for removal.

In the semiconductor device manufactured in this way, the polymer deposited after etching the metal wiring and peeling off the resist is completely removed by ozone treatment, so there is no peeling or cracking of the interlayer insulating film or passivation film as in the past. We were also able to improve long-term reliability.

The polymer removal effect becomes clear from an ozone concentration of about 2%, and the higher the concentration, the higher the removal rate. Although it is not sensitive to processing temperature,
It is preferable to use a temperature of about 450° C. or higher, which does not affect the metal wiring or PN junction. Also, this ozone treatment
Considering processing efficiency, continuous processing was carried out in the same chamber of an electrophase growth apparatus equipped with high-frequency parallel plate electrodes, but it may also be carried out in different apparatuses, especially when vapor-phase growing an insulating film.
In order to suppress hillocks in metal wiring, the effect is more pronounced as the heat time required from setting the semiconductor substrate in the device to the start of reaction growth is reduced, and therefore single-wafer vapor phase growth is performed. sometimes especially useful.

Furthermore, the vapor-phase grown film contains not only 5iHa, N, and O, but also S.
It may be made by subjecting iH, or organic silane to a plasma reaction or thermal reaction of ozone, or a composite film of these may also be used.

The present invention is applicable not only to multilayer wiring structures, but also to MO3ICs, bipolar, 0MO3, and (combined ICs) in which an insulating film is formed on metal wiring.Furthermore, the metal wiring is not limited to Aff alloy, Other metals, silicides, and semiconductor materials may be used. In addition, high-melting point metals such as Ti, W, Co, and Mo, or their nitrides, silicides, and alloy films may be laminated for flattening and contact barrier purposes. It is applicable.

[Effects of the Invention] As described above, according to the present invention, by performing ozone treatment before forming an insulating film on metal wiring such as MO3LSI, contamination products are removed and characteristics related to the quality of the insulating film itself are improved. This improves the reliability by 4 m and contributes to the supply of more miniaturized and more sophisticated semiconductor devices.

[Brief explanation of the drawing]

FIGS. 1A and 1B are schematic cross-sectional views showing an embodiment 15!1 of a semiconductor device according to the present invention. FIGS. 2(a) to 2(c) are schematic cross-sectional views of conventional semiconductor devices. 11, 21 12, 22 13, 23 14, 24 15, 25 16, 26 17.27 18.28 19, 29 - Semiconductor substrate - First field oxide film - Second field oxide film - First metal wiring・Photoresist ・Polymer ・Interlayer insulation film ・Coated glass ・Second metal wiring jl! Figure 1 (1: i! Figure 1 (b)! Figure II ((, 1 or more

Claims (1)

[Claims] It is characterized by having at least the steps of patterning the metal wiring by dry etching, peeling off the mask resist, heat treatment in an atmosphere containing ozone gas, and laminating an insulating film by vapor deposition or coating. A method for manufacturing a semiconductor device.